Head-Mounted Device

5. The head-mounted device according to claim 4, wherein both of the first head band and the second head band are provided with a length adjustment hole at the overlapping portion, the length adjustment hole is a strip-shaped through hole, and each of the first head band and the second head band is provided with sawtooth wave extending along the length direction of the strip-shaped through hole in the length adjustment hole, the gear is disposed in the length adjustment hole and meshed with the sawtooth wave of each of the first head band and second head band, to adjust the overlapping length of the first head band and second head band.

6. The head-mounted device according to claim 4, wherein the mounting portion comprises two shielding plates disposed opposite and fixedly mounted, and the rotating plate is disposed between the two shielding plates; the pawl is pivoted on the shielding plate.

8. The head-mounted device according to claim 7, wherein the pawl comprises a corner at a side away from the elastic member, and the corner is configured to engage with the inner teeth of the ratchet.

9. The head-mounted device according to claim 7, wherein the two shielding plates are provided with a restriction portion on the rotation path of the rotating plate, the rotating plate is provided with a notch matched with the restriction portion, and the restriction portion is located in the notch, the restriction portion is configured in two states of contact and non-contact with the inner wall of the notch, so that the rotating plate is rotated by a fixed angle around a rotation axis of the rotating plate.

10. The head-mounted device according to claim 9, wherein the rotating plate has an outer wall surface, the outer wall surface is curved and configured to: when the rotating plate rotates around the rotation axis, the outer wall surface pushes the pawl to rotate, so that the pawl and the ratchet switch between the engagement and unengagement.

11. The head-mounted device according to claim 10, wherein the number of pawls is two, and the two pawls are symmetrically disposed relative to the two sides of the rotating plate.

12. The head-mounted device according to claim 7, wherein the gear is fixedly mounted on one of the two shielding plates, and the axis of gear is coaxial with the rotation axis of the rotating plate.

13. The head-mounted device according to claim 6, wherein the middle of the pawl is rotationally connected with a mounting shaft, one end of the mounting shaft is fixedly mounted on one of the two shielding plates, and the other end of the mounting shaft contacts with the other of the two shielding plates.

16. The head-mounted device according to claim 15, wherein the outer diameter of the disk is larger than the outer diameter of the first connecting shaft, and the radius of the disk is larger than the radius of the gear.

20. The head-mounted device according to claim 18, wherein the force bearing member is connected with the second housing and located on one side of the ring-shaped frame; the force bearing member comprises a fixing plate and a soft pad wrapping the mounting plate; the fixing plate is fixed on the second housing.